Quantized conductance and its correlation to the supercurrent in a nanowire connected to superconductors

TL;DR

This study investigates how quantized conductance in InAs nanowires correlates with supercurrent when connected to superconductors, revealing stepwise decreases in conductance and critical current as channels are depleted.

Contribution

It demonstrates the direct correlation between quantized conductance steps and supercurrent reduction in nanowires with tunable charge density.

Findings

Conductance and supercurrent decrease stepwise with gate voltage.

Quantized conductance correlates with discrete changes in supercurrent.

Complete conductance suppression coincides with the disappearance of supercurrent.

Abstract

We report conductance and supercurrent of InAs nanowires coupled to Al-superconducting electrodes with short channel lengths and good Ohmic contacts. The nanowires are suspended 15\,nm above a local gate electrode. The charge density in the nanowires can be controlled by a small change in the gate voltage. For large negative gate voltages, the number of conducting channels is reduced gradually and we observe a stepwise decrease of both conductance and critical current before the conductance vanishes completely.